Subscribe for more tech videos.Just as we've come to expect from Panasonic's autofocus setup, it's quick and reliable. Whether using the automated 49-area array, one-point, or pinpoint modes it's a familiar and snappy experience, just like the Lumix GH4. There are also face/eye detection, tracking, and a custom multi mode (which offers multiple user-selected points to be activated) options.Low-light is rarely an issue for focus, whichever AF mode is selected, and we've been shooting ISO 6400 frames in the dark cells of Alcatraz prison, through to sun-drentched tourist shots around the city. Although the "Light Speed AF" term isn't banded around any more, it does feel lightning quick.Coupled with the touchscreen it's possible to tap-to-focus anywhere on the screen, which is great, although it's all too easy to move the focus point by accident when adjusting the vari-angle screen's position, which can become tiresome – but that's part and parcel of such a feature. Sometimes our face would end up shifting the focus point position on the screen when pulling away from the viewfinder, which wasn't ideal when coming back to take a shot again later. But if you don't want it, simply deactivate the feature within the settings.

4K fanaticPanasonic's other big push is all about 4K. From ultra-high definition video capture, to what the company calls "4K Photo", it's got the same set of features as the Lumix G7 in this department.And our thoughts about it are much the same: we're unconvinced by the name's misdirection, as all the camera is doing for 4K Photo is shooting an MP4 clip, from which still images can be extracted using touch-based in-camera software (or in post if you want to muck about with Photoshop). The in-camera software works really well, as it's possible to swipe through clips frame by frame using a finger on the rear screen. But if you're used to simply opening stills in Lightroom or another programme, then the experience feels altogether different.The GX8 doesn't have a dedicated 4K mode on a dial, though, it's instead accessed through the drive menu. And as there's no dedicated drive mode dial, as per the G7, this isn't as readily accessible as we would like.Image qualityAll this goodness and then there's that new higher-resolution sensor to take on board, pushing Micro Four Thirds beyond the 20-megapixel boundary for the first time.Initially we weren't convinced that a boost beyond the earlier G-series' 16-megapixel limit was necessary, but having previously spotted colour noise apparent in some of the low-mid sensitivities it's good to see the GX8 appears to offer cleaner images.

In an ISO 400 long exposure facing over Ghiradelli square the blacks are deep and true, without presence of interfering colour noise within the shadow areas. An ISO 800 shot of fermentation tanks at Anchor brewery appears similarly clean, with only the subtlest presence of such noise in the mid-grey areas to the corners.